Pritzker, who is fully vaccinated and double boosted, received the positive result during his routine testing regimen after several people he had close contact with also contracted the virus.
He has been prescribed the anti-viral medication Paxlovid.
"[Pritzker] looks forward to returning to in person work as soon as possible," his office said in a statement.
Pritzker on Saturday delivered an address at Florida Democrats’ annual Leadership Blue Gala. U.S. Rep. Val Demings, D-Fla., also tested positive after attending the event. The address, along with another political speech delivered before the New Hampshire Democratic Party last month, is ramping up suspicions that Pritzker is considering a presidential run.
As of last Friday, the Illinois Department of Public Health reported that nearly half of all counties in Illinois are at "high community level" for COVID-19 and of the rest, all but eight counties are at "medium community level." The Public Health Department recommends people use caution and wear a face covering when indoors.
Since early 2020, Illinois has recorded 3.496 million cases of COVID-19. The illness has contributed to 34,257 deaths.
Sun-Times Media Wire and Associated Press contributed to this report.